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Finding the Fourth Proportional to 663.90, 915.50 and 478.28

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Solution

The fourth proportional to 663.90, 915.50 and 478.28 is: 659.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.90 : 915.50 = 478.28 : x
  2. Step 2: Convert to fraction form
    663.90/915.50 = 478.28/x
  3. Step 3: Cross multiply
    663.90x = 915.50 × 478.28
  4. Step 4: Simplify right side
    663.90x = 437,865.34
  5. Step 5: Solve for x
    x = 437,865.34/663.90
  6. Step 6: Final answer
    x = 659.54

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.